Cost-Effective IIoT Gateway Development Using ESP32 for Industrial Applications

Abstract

The Industrial Internet of Things (IIoT) connects industrial devices, such as measuring equipment and production line machines, to the Cloud system via the internet, creating a database for equipment data storage and performance analysis. Implementing an IIoT system requires an IIoT Gateway to interface with industrial controllers using protocols like Modbus TCP/IP or OPC UA, enabling data transmission to the Cloud. These Gateways, often produced by PLC manufacturers, are typically expensive. This research investigates using an ESP32 microcontroller as a cost-effective alternative to the Simatic IOT2050 IIoT Gateway. The study focuses on connecting the Siemens Simatic S7-1200 12144C AC/DC/RLY PLC via Modbus TCP/IP and facilitating data transmission between cloud systems using MQTT and REST API protocols. Results show that the IIoT Gateway's response time for writing 16-bit payload data to the PLC via Modbus TCP/IP averages 0.0591 seconds. Additionally, the device supports data scaling from 16-bit Integer to 32-bit Float for Modbus TCP/IP communication and converting 32-bit Float data to Message data for transmission via MQTT to ThingSpeak Cloud and REST APIs to Blynk Cloud. This approach offers a viable, cost-effective solution for IIoT implementations.